National Safety Council. (1956). Supervisors safety manual; better production without injury and waste from accidents. s.n.
Citação do estilo Chicago (17ª ed.)National Safety Council. Supervisors Safety Manual; Better Production Without Injury and Waste from Accidents. Chicago: s.n, 1956.
Citação MLA (9ª ed.)National Safety Council. Supervisors Safety Manual; Better Production Without Injury and Waste from Accidents. s.n, 1956.
Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.